OSSM-hardware
Instructions
Required tools:
- 8mm drill bit
- M8 tap
- Metal saw for cutting the 4040 extrusion
- M8 allen wrench
- M6 allen wrench
Optional tools:
- Round metal file
- Cutting oil
Required Hardware: | Quantity | Item | Notes | | ——– | —- | —– | | 1 | M6 x 30mm clamp handle locking lever | for tensioning the motor clamp. | | 1 | M6 T Nut | for securing the M6 x 30mm clamp lever on the motor clamp | | 1 | M6 x 20mm bolt | for bolting fixed side of motor clamp the extrusion. | | 1 | M6 T Nut | for securing the M6 x 20mm bolt to the motor clamp | | 2 | M6 x 20mm bolt | for attaching the carrying handle | double check the length of these | 2 | M6 T Nut | for securing the M6 x 20mm bolts to the carrying handle | | 12 | M6 x 20mm bolt | for bolting hinge plate to the 4040 extrusion. | | 12 | M6 x T nut | for bolting hinge plate to the 4040 extrusion. | | 2 | Knob Grip M8 x 60mm bolt | Used to fasten legs to the ends of the base extrusion. | | 2 | M8 x 70mm bolt | for securing the hinge plate to the hinges. | | 2 | M8 nut | for fastening the M8 bolts. | | 2 | M8 x 70mm clamp handle locking levers | For tensioning the arms. | | 2 | M8 T nut | for fastening the M8 Handled Clamps. | | 6 | 25mm M8 washer | For the hinges. Two per M8 bolt, and one per M8 locking lever bolt. | | X | Aluminum Extrusion. Suggested lengths are Two 400mm and Three 475mm, but you can choose what you would like. Pay attention to the extrusion profile that you purchase, there are many kinds! (T Slot vs V slot, I-Type vs B-Type) The default files for this mount use B-Type slots. |
Note:
You need 15 M6 x 20mm bolts total
You need 16 M6 T Nuts total
Required Printed Parts:
- One set motor rings and clamp (the motor ring is made of two parts. Print these at at least 50% infill) – nema23 motor mount-ridge-internal fron bolt v3.stl
- Two leg connectors (Print at 100% infill) – 4040-t-conector v3.stl
- Four long hinges (don’t bother with the smaller hinges, they complicate it unnecessarily) – hinge-long v1.stl
- Four hinge plates (Print at 100% infill, the added strength is worth the print time) – hinge-plate.stl
- Eight end caps – 4040 end cap v7.stl
- Two leg stores – leg-store v3.stl
- One carrying handle (Print at 100% infill) – handle v2.stl
- Two power supply holders (if you have a MEAN WELL GST220A36-R7B) – PSU-clamp v5.stl
Assembly:
If you didn’t buy the extrusion pre-cut, start by cutting it to length.
Suggested Aluminum Extrusion lengths:
Two 400mm lengths for legs.
Three 475mm lengths (one for the base and two for arms).
Note: The Extrusion type in the example pictures is from 8020.net and is I-Type solid slot 5, which does not match the default STL files. You’ll need to use the modified hinges and end caps. These have not been uploaded yet as of 4/30/2023
The base will be an H Shape, with the two 400mm lengths being the vertical bars of the H shape, and one 475mm length to be the horizontal bar.
Use the M8 tap to cut threads into the existing holes on each end of one of the three 475mm extrusions that will be used the base.
Find the center of the 400mm legs and mark it in the channel. Slide a leg connector into the extrusion channel so the hole of the leg connector is aligned with the center mark on the extrusion. Use the leg connector as a guide for drilling the 8mm hole through
the center of the extrusion. You may want to use cutting oil to make drilling easier. Be sure to clean up the burrs and shavings with a metal file.
Next we will drill the holes on the 475mm arms for the hinges. Insert the long hinge into the extrusion channel so that the round pivot point end is flush with
the cut end of the extrusion. Drill two 8mm holes through the 4040 using the holes on the long hinge as a guide.
It may be easer to drill half way through from one side and then insert another long hinge on the opposite side and finish drilling through from the other side.
Repeat this step one more time and drill two more holes in the second 475mm arm using another long hinge as a guide. Insert the remaining long hinge into the channels with the drilled holes, again with the round pivot end is flush with the cut end of the extrusion.
The hinge is first assembled by pressing the hinge plate onto the round knob of the long hinge insert. This might take some force, you can use some liquid dish soap to make it a little easier.
Pay close attention to the direction of the hinge plates do you don’t match them up backwards. Repeat this until all of the hinge plates are mounted.
Add an M8 x 70mm bolt with an M8 25mm washer on both sides then fasten with an M8 nut. Next insert the M8 x 70mm clamp lever to the other hole, you may want to add an M8 25mm washer on the clamp side. Fasten the M8 clamp lever with a T nut so that the wings of the T rest against the hinge plate and the spur sits in the curved channel. Thread the three M6 x 20mm bolts into the three holes at the bottom of the hinge plates, then thread the the M6 T nuts onto the M6 bolts so that they are all sideways to make it easier to slide into the extrusion channel. Repeat this once more for the remaining two hinge plates.
Align the T nuts so they are sideways to allow them to easily slide into the extrusion.
The T nuts slide in much easier this way.
Note the picture below does not have an M8 25mm washer as I happened to use an M8 Flange nut. You may need to use a washer if you don’t have flange nuts. The damage to the hinge plate is from me experimenting with other fasteners, I would not expect the same thing to happen to you.
Now you will have the two arms with hinge plates mostly assembled.
Choose one of the arms as the top arm and attach the carrying handle by threading M6 x 20mm bolts into each hole of the handle, then thread the M6 T nuts onto the bolts. Slide the T nuts into the extrusion channel until the handle is about midway, then tighten the bolts down. The T nuts should turn in the channel and hold in place. We will move on to the lower arm next and slide the T nuts at the bottom of the hinge plates of the lower arm onto the 475mm base that has the M8 threads cut. Slide a leg keeper into the each side of the base, these will help make the footprint smaller when storing the OSSM.
If you are using the Power Supply mount then you will need to put the leg keepers on the same side instead; one leg keeper would go on the base and the other leg keeper would go on the lower arm. The two Power Supply mounts would slide into the extrusion channel of the base opposite of the side you have the leg store on.
Attach the legs to the base extrusion by pressing the two protruding prongs of the leg connector into the channels of the cut face of the base extrusion then threading the M8 knob bolts through the hole.
Your base and legs should now make the H shape with the lower arm loosely attached to the base. Tighten the six M6 bolts, making sure the T nuts turn in the extrusion channel.
Do the same for the top arm, sliding the the hinge plate T nuts onto the opposite end of the lower arms hinge plate. Tighten the M6 bolts, the T nuts should turn and catch in the channel.
Your mount should now be nearly complete! The remaining steps are to attach the OSSM!
Fit the motor rings around the servo body and press into the round clamp. Push an M6 x 20mm bolt into the closed end of the clamp and an M6 x 30mm clamp handle bolt into the open end. Thread on M6 T nuts and carefully slide the mount ring into the extrusion channel. Secure it in place by tightening down the back M6 x 20mm bolt. You can tighten the M6 clamp bolt by pulling upwards on the clamp handle to compress the spring and use an allen wrench to turn the bolt itself until the T nut begins to snug. Slow down and carefully turn the bolt until the OSSM will no longer rotate in the mount. Release the lever in the tightened position, then you can loosen it and the OSSM should be able to rotate in the collar.
You are done!
To store, unscrew the M8 knob bolts and remove the legs, then push the leg mount prongs into the leg keepers and tighten the M8 bolts until secured.
